We have several designs that are working with the MP6500L part. They have no issues whatsoever, so we started a new design and now we’re working with the first set of boards and were having problems that we’ve never seen before. The motor is squealing / stepping on its own with no step input.
The fault pin never goes low. I’ve attached Layout and a screenshot of the ISET voltage. On a good board, this does not have any pulses that go to zero.
I’ve also attached some screenshots of the good PCB layout vs. the one that’s not working. The only real difference I see between them is that the VIN decoupling caps are farther away on the non-working board and there is not a via in the ground pad. Could those be enough differences to cause this issue?
Sorry, it looks like I can only embed one image as a new user. Maybe I can post the layout images in another post?
